Hobbies And Interests
The Principle Behined Lock Gates
If a river descends a slope, it tends to flow at a rate that is unsafe for most river-going vessels. Rapids and other hazards also appear on stretches of fast-flowing water. Engineers overcome this problem by building lock gates. Essentially this is a section of river that can be sealed at each end by a gate. If a boat is coming from upstream then, with both goats closed, small channels in the lower gate are sealed while those in the upper gate are opened, which allows the sealed section to fill up with water until the water in the sealed section is at the same height as the river upstream. The top gate is then opened and the boat is admitted into the sealed section. At this point, the channels in the top gate are closed, and the channels in the bottom gate are opened. The water gradually drains out, and the water level in the sealed section slowly descends until it is level with the river downstream of the lock gate. The bottom gate is then opened, and the boat is allowed to pass through. For a boat heading upstream, the procedure is reversed.
Making Model Lock Gates: The Base
Science projects are generally expected to involve some sort of practical demonstration of a scientific or technological principal. Making a working model of a lock gate is not too challenging, but if you try to make anything too elaborate, you will probably end up with a lot of leaks, which will ruin the project. A good way to avoid this is to keep the design simple, and use something that is already watertight to build with. One approach is to cut the bottoms off milk or juice cartoons and stick them together to form a series of chambers. If you make a shallow-sloped staircase from scrap wood and position the chambers at staggered heights descending the staircase, you have a pretty good model of a flight of locks; now all you need is some lock gates to let the boats up and down.
Making Model Lock Gates: The Components
Again, the more complicated you make your lock gates, the more likely you are to have problems with leakages. However, keeping the design simple is not a problem as what you are trying to communicate is the principal behind the design, and the simpler the model, the more clearly it explains the principal at work. All you need in this case is to cut simple doors in the adjoining walls between the sections, and poke a hole in the wall at the same level as the bottom of each gate. Make the bottom edges of the gates a little lower on the downstream side of the chamber than on the upstream side, and simply seal the seams and holes with modeling clay. However, if you want to try to make something a bit more technical, feel free to experiment; just ensure you have a foolproof way of sealing any gaps.
Operating Your Model
To operate your model, you will simply need to fill all the chambers up to the level of the lower gate, then, starting at the top chamber, allow the water to drain from the higher chamber into the lower until the water on each side is level. At this point, you can move a model boat or just a cork through the gate and run the same procedure again. You'll need a hosepipe or water bucket on hand to fill the system up and a container to catch water from the bottom of the system.
Presenting Your Work
The model on its own isn't really enough for a good science fair project; you need a poster explaining what is going on and where the energy comes from to lift the boat up the lock system. This is your chance to show some deeper scientific understanding. The energy is produced by the water under gravitational force as it flows downstream. However, the energy that carried it upstream in the first place comes from the heat of the sun, causing water to evaporate and creating wind which blow the clouds to the point where the rain falls.